1. Field of the Invention
The present invention relates to liquid crystal displays, and more specifically to a liquid crystal display including a common voltage regenerator, and to a driving method thereof.
2. General Background
Liquid crystal displays (LCD) display a clear and sharp image through thousands or even millions of individual pixels. The liquid crystal display has thus been applied to various electronic devices, such as mobile phones and notebook computers.
FIG. 5 is an abbreviated circuit diagram of a typical liquid crystal display 10. The liquid crystal display 10 includes a liquid crystal panel 11, a gate driving circuit 13, a data driving circuit 14, and a common voltage generator 15. The gate driving circuit 13 and the data driving circuit 14 drive the liquid crystal panel 11. The common voltage generator 15 provides a common voltage for the liquid crystal panel 11.
The liquid crystal panel 111 includes a plurality of parallel gate lines 131, each extending along a first axis, a plurality of parallel data lines 141 extending along a second axis orthogonal to the first axis, and a common line 101. The intersecting gate lines 131 and data lines 141 define an array of pixel units 102.
Each pixel unit 102 includes a thin film transistor (TFT) 1021 provided in the vicinity of a point of intersection of a gate line 131 and data line 141, a liquid crystal capacitor 1022, and a storage capacitor 1023. The liquid crystal capacitor 1022 includes a pixel electrode 1025, a common electrode 1026 facing the pixel electrode 1025, and a liquid crystal layer (not shown) sandwiched therebetween. Each storage capacitor 1023 includes the pixel electrode 1025, a storage electrode 1027, and insulating material sandwiched therebetween. A gate electrode, a source electrode, and a drain electrode of the TFT 1021 are connected to a corresponding gate line 131, a corresponding data line 141, and the pixel electrode 1025 respectively.
When the liquid crystal display 10 functions normally, the gate driving circuit 13 provides a plurality of scanning signals to the gate lines 131 in sequence, such that the TFTs 1021 connected to the gate lines 131 are switched on. At the same time, the data driving circuit 14 provides a plurality of gradation voltages to the data lines 141. The gradation voltages are applied to the pixel electrodes 1025 via the source and drain electrodes of the activated TFTs 1021. The common voltage generator 15 generates a common voltage, and provides the common voltage to the common electrode 1026 and the storage electrode 1027 via the common line 101. The common voltage is generally a 5v direct current (DC) voltage.
However, the common voltage of the liquid crystal display 10 susceptible to influence by a variety of coupling capacitances. As a result, ripples in the common voltage occur, resulting in crosstalk, whereby display quality of the liquid crystal display 10 is impaired.
Therefore, a liquid crystal display that can overcome the limitations described is desired.